Though no orbit is perfectly circular, the general name for any orbit
that is not highly elliptical (egg-shaped) is circular. Circular orbits
have an eccentricity of 0. There are several
types of circular orbits and they include:

The orbital path of satellites in these circular orbits is also affected
by the satellite's altitude - its height above the Earth. Satellites in
geostationary orbit are always in a high orbit. If the satellite is in a
polar, sun-synchronous, or equatorial orbit, its orbital altitude may be
medium or it may be low. Since the altitude determines the speed of the
orbit, the time it takes a satellite to complete one orbit, and the clarity
with which the satellite can see the Earth, there are advantages to each
type of orbit and each orbital height.